This invention relates to the decontamination of surfaces and particularly, but not exclusively, to the removal of technetium from surfaces of aluminum containing components.
Aluminum components used in nuclear plants, especially enrichment plants, become contaminated with, for example, uranium, neptunium and technetium.sup.99. The bulk of the uranium and neptunium present on the surface of a component can be removed using a wet chemical route incorporating a chelating agent.
In the case of technetium, it is highly desirable to remove not only technetium on the surface of the component but also technetium bound under a layer of aluminium oxide present on the surface of the component. The presence of the oxide layer renders the trapped technetium inaccessible to the chemicals used to remove uranium from the surfaces of components. With technetium a further problem is encountered which is not encountered with uranium, in that a slight build up of technetium in the decontamination liquor results in some of the technetium plating back onto the surface. Consequently, the route used to remove uranium from the surfaces of components cannot be used to efficiently remove technetium from those surfaces.